Mail Archives: pgcc/2002/08/08/09:30:08
On Thu, 08 Aug 2002, a DOT bohne AT dkfz-heidelberg DOT de (Andreas Bohne) wrote:
> Date: Thu, 08 Aug 2002 14:35:53 +0200 (CEST)
> To: pgcc AT delorie DOT com, a DOT bohne AT dkfz-heidelberg DOT de
> From: a DOT bohne AT dkfz-heidelberg DOT de (Andreas Bohne)
> Reply-To: pgcc AT delorie DOT com
> Subject: bug? in pg77
>
> Hi,
>
> we are working in science I wanted to run a molecular dynamic simulation.
> It is a free software called Tinker and it is written in Fortran 77.
>
> I did run some benchmarks and now look:
>
> g77:
> real 63m41.531s
> user 63m25.240s
> sys 0m4.730s
>
>
>
> pg77:
>
> real 922m12.183s !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
> user 917m50.840s
> sys 0m54.250s
>
>
> For compiling I did use :
> CC="pg77"
> OPTI="-O3 -funroll-all-loops -ffast-math -march=i686 -mcpu=i686 "
Although you may try to play with the optimization options, just don't use
PGCC anymore - newer GCC versions optimize as good, most likely even better
as PGCC 2.95.2 on Pentium (and up) CPUs.
Nevertheless I am scared that g77 from PGCC produces THAT bad code, but I
only used the C and C++ compilers extensively and as PGCC development has
AFAIK been stopped for the reason above, just go with GCC 3.x.
- Sebastian
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